Dual-Train Wastewater Reclamation and Treatment System

ABSTRACT

A wastewater treatment system for use on marine vessels or land-based applications where wastewater is separated into two separate sources as graywater and raw sewage (blackwater). For blackwater, the treatment system incorporates five general phases (or zones): (1) screening, (2) clarifying, (3) filtering, (4) advanced oxidation, and (5) sludge reducing. For graywater, the treatment system incorporates three general phases (or zones): (1) screening (2) filtering, and (3) advanced oxidation. Each train of the treatment system (blackwater and graywater) can operate as a stand-alone system or can be assimilated into an integrated treatment train for both graywater and blackwater. This system is particularly useful in today&#39;s restrictive regulatory environment.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority co-pending non-provisionalapplication entitled “Dual-Train Wastewater Reclamation and TreatmentSystem”, Ser. No. 11/276,880, filed by inventors Randall J. Jones andStephen P. Markle on Mar. 17, 2006, which claimed priority to thenco-pending United States provisional patent application entitled“Advanced Oxidation System For Wastewater Treatment,” having Ser. No.60/665,736, filed by inventor Randall Jones on Mar. 28, 2005, and thenco-pending United States provisional patent application entitled“Dual-Train Wastewater Reclamation and Treatment System,” having Ser.No. 60/777,520, filed by inventors Randall J. Jones and Stephen P.Markle on Feb. 24, 2006, all of which are entirely incorporated hereinby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to wastewater treatment systems,and more particularly wastewater treatment systems where holding largevolumes of sludge for later disposal is difficult. As such, thisinvention particularly relates to waste water treatment for ships,off-shore structures and platforms other large transportation vehicles,mobile/portable treatment systems (i.e., military support, disasterrelief, etc.), remote treatment systems (i.e. highway rest stops,campgrounds, etc.), industrial wastewater treatment, food processing,dairy and other light industrial wastewater treatment applications.

2. Discussion of the Related Art

Land-based wastewater treatment solutions tend to occupy relativelylarge spaces to effectuate wastewater treatment. Space, however, is apremium on transportation vehicles (like cruise ships), mobile treatmentsystems (such as used in military support), and remote treatment systems(like campgrounds), as well as other similarly situated treatmentscenarios.

Ordinarily, wastewater systems combine blackwater and graywater prior totreatment. Blackwater and graywater, however, are very different interms of chemical makeup (composition, viscosity), volume, perception bypassengers and crew, and treatment under the law. For example,blackwater must be treated to a higher standard in most operating areas.Most ships are fitted with vacuum flush systems with blackwaterpollutant concentrations much greater than those found in graywater.Shipboard water production, storage and management necessitates costlyinfrastructure.

Shipboard wastewater systems are typically based on biologicaltreatment. While biological based systems can work, biological systemsare complicated to operate, have a large footprint in terms of tankageand deck space, are susceptible to periodic chemical upsets, can beexpensive to operate due to costs of chemicals, require provisioning ofthese chemicals, have long start-up times (order of days) and producelarge amounts of sludge.

Finally, discharge of wastewater is regulated. Compliance withregulations can be difficult and may require holding volumes ofwastewater for days to complete Biochemical Oxygen Demand (BOD) testingand other compliance testing. If the treated wastewater ultimately failscompliance testing, the process must be continued, which results in losttime and requires larger holding tanks.

Wastewater treatment systems have been disclosed in the following UnitedStates or foreign patents: U.S. Pat. No. 3,822,786 (Marschall), U.S.Pat. No. 3,945,918 (Kirk), U.S. Pat. No. 4,053,399 (Donnelly et al.),U.S. Pat. No. 4,072,613 (Alig), U.S. Pat. No. 4,156,648 (Kuepper), U.S.Pat. No. 4,197,200 (Alig), U.S. Pat. No. 4,214,887 (van Gelder), U.S.Pat. No. 4,233,152 (Hill et al.), U.S. Pat. No. 4,255,262 (O'Cheskey etal.), U.S. Pat. No. 4,961,857 (Ottengraf et al.), U.S. Pat. No.5,053,140 (Hurst), U.S. Pat. No. 5,178,755 (LaCrosse), U.S. Pat. No.5,180,499 (Hinson et al.), U.S. Pat. No. 5,256,299 (Wang et al.), U.S.Pat. No. 5,308,480 (Hinson et al.), U.S. Pat. No. 6,811,705 (Puetter),EPO 261822 (Garrett), WO 93/24413 (Hinson) and U.S. Pat. No. 6,195,825(Jones). None of these references, however, disclose the aspects of thecurrent invention.

What is needed is a wastewater treatment system that has a smallfootprint, produces dischargeable effluent minutes after startup,requires virtually no chemical additions, is simple to operate,minimizes sludge production from biological activity, is constructed ofthe most durable components, and produces a high quality effluentexceeding most stringent effluent requirements day-after-day. What isalso needed is a wastewater treatment system that can treat the samevolume of wastewater in a smaller space and/or in faster time thancurrently existing systems to reduce the space occupied by holding tanksand treatment equipment.

What is also needed is a system that can accurately predict treatmentcompliance results to enable more efficient and predictable compliancesuccess.

SUMMARY OF THE INVENTION

The invention is summarized below only for purposes of introducingembodiments of the invention. The ultimate scope of the invention is tobe limited only to the claims that follow the specification.

Generally, the present invention is incorporated in an integrated, splittreatment system that treats blackwater for compliance and sludgereduction and treats graywater for reuse, blending and compliance(referred herein as the “dual-train water reclamation and treatmentsystem” or “treatment system”). For blackwater, the treatment systemincorporates five general phases (or zones): (1) screening, (2)clarifying, (3) filtering, (4) advanced oxidation, and (5) sludgereducing. For graywater, the treatment system incorporates three generalphases (or zones): (1) screening (2) filtering, and (3) advancedoxidation. Each train of the treatment system (blackwater and graywater)can operate as a stand-alone system or can be assimilated into anintegrated treatment train for both graywater and blackwater. Thissystem is particularly useful in today's restrictive regulatoryenvironment.

One advantage of the treatment system is the ability to treat blackwaterdifferently from graywater. Reuse of graywater is becoming more sociallyacceptable; blackwater reuse is not. Moreover, reuse of reclaimed sewagealso bears the risk to human health associated with equipment failure.

Another advantage of the treatment system is that it reduces the spaceneeded for wastewater treatment, and space is a premium for mobile unitslike cruise ships and other aquatic vessels. The system is compact insize, simple in design, inexpensive to operate, built for long termreliable operation in the marine environment, hatchable, and modular inconstruction affording ease of tailoring with selection of correctnumber of standardized modules.

Another advantage of the water reclamation and treatment system is theuse of turbidity, UV transmittance and ORP readings to predict final BODlevels for compliance or non-compliance in advance of the compliancetest results to enable a more predictable and efficient treatment. Inaddition, it affords reach-back, real-time monitoring of effluentquality.

Another advantage of the water reclamation and treatment system is theability to handle wastewater that lacks predictable levels ofcontamination and pH. Ferries or military vessels may wait for manyhours, days, weeks, or even months between heavy loading events. Thistype of varied influent can greatly affect a biological based treatmentsystem. Among other things, a varied influent causes a lengthy period oflimited effectiveness while biological colonies reform. Unlike thebiological systems in use in many of these applications, varied influentdoes not affect the water reclamation and treatment system. In thiscase, the treatment system immediately reacts and begins treatmentwithout regard to effluent strength or pH. In addition, biologicaltreatment systems typically require a fixed amount of time (1-2 weeks)to establish a viable colony for wastewater treatment. In this case, thewater reclamation and treatment system begins treating wastewaterimmediately after system startup.

The description of the invention that follows, together with theaccompanying drawings, should not be construed as limiting the inventionto the example shown and described, because those skilled in the art towhich this invention pertains will be able to devise other forms thereofwithin the ambit of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of an integrated water reclamation andtreatment system 10.

FIG. 2 is a flow chart that reflects an embodiment of a blackwatertreatment train 100.

FIG. 3 a flow chart that reflects an embodiment of a graywater treatmenttrain 200.

FIG. 4 illustrates an embodiment of a blackwater clarifying zone 120 anda sludge reduction zone 170.

FIG. 5 illustrates an embodiment of a stirred reactor 300.

FIG. 6 illustrates an embodiment footprint/plan for a 20-gpm blackwatertreatment train 100.

FIG. 7 illustrates an embodiment footprint/plan for a 30-gpm blackwatertreatment train 100.

FIG. 8 illustrates an embodiment footprint/plan for a 25-gpm graywatertreatment train 200.

FIG. 9 illustrates an embodiment footprint/plan for a 100-gpm graywatertreatment train 200.

FIG. 10 illustrates an embodiment of the modularity of the system 10.

FIG. 11 is a flow chart that reflects an embodiment of an alternateblackwater treatment train 100.

FIG. 12 is a flow chart that illustrates a functional diagram of flowzones of the system.

DESCRIPTION OF PREFERRED EMBODIMENT

The descriptions below are merely illustrative of the presentlypreferred embodiments of the invention and no limitations are intendedto the detail of construction or design herein shown other than asdefined in the appended claims. In this specification, the term“graywater” refers to discarded liquid from sources such as deck drains,lavatories, showers, dishwashers, laundries, drinking fountains andpotentially equipment cooling water. “Graywater” does not includeindustrial wastes, infectious wastes, human body wastes, and animalwaste. In this specification, the term “blackwater” refers to sourcessuch as wastes of human origin from water closets (toilets), urinals,and medical facilities transported by the ships soiled drain system(a/k/a sewage). It also includes animal wastes from spaces containinglive animals. When graywater is combined with blackwater, the wastestream is characterized as blackwater. In this specification, the term“technical water” includes water for laundry, flushing water, coolingwater, vehicle wash, etc. In this specification, the term “advancedoxidation” refers to a process that typically involves the generationand use of the hydroxyl free radical (OH⁻) as a strong oxidant todestroy compounds that cannot be oxidized by conventional oxidants suchas oxygen, ozone, and chlorine.

General Design Overview

The water reclamation and treatment system 10 splits treatment into ablackwater treatment train 100 and a graywater treatment train 200. Bysplitting the treatment of blackwater and graywater, the treatmentsystem can reclaim graywater for reuse. Reusing graywater offers severaladvantages. Among other things, reusing graywater (1) reduces freshwater making requirement/consumption, (2) reduces plant operating costs,(3) reduces tankage requirement (and ultimately the treatmentfootprint), (4) reduces ship propulsion plant costs by reduced shipdisplacement resulting from smaller tankage requirements, (5) protectsthe environment, and (6) reduces the volume of wastewater needing toundergo blackwater treatment.

The graywater and blackwater treatment trains differ in arrangement dueto the unique differences of the influent treated. The principledifference is the location where filtration occurs. In graywater trains,filtration preferably occurs prior to advanced oxidation. In blackwatertrains, filtration preferably depends on the level of total suspendedsolids (TSS). For blackwater with TSS less than 500 parts per million(PPM), filtration preferably occurs post-advanced oxidation. Forblackwater with TSS greater than 500 parts per million (PPM), filtrationpreferably occurs prior to advanced oxidation.

FIG. 1 provides an example embodiment of an integrated dual train systemdesigned for shipboard use. Of course, the system shown in FIGS. 1-12could be adapted for other uses (such as land-based uses) as well asother wastewater volumes and loading conditions. FIG. 12 illustrates thefour principle zones of the water reclamation and treatment system 10.Whether as an integrated system or as a standalone system, the waterreclamation and treatment system 10 comprises: a solids separation zone,a filtration zone, and an advanced oxidation zone, with the option ofadding a sludge reduction zone.

Preferred Blackwater Treatment Train

The blackwater treatment train 100 can be used as a standalone system totreat wastewater. Alternatively, the blackwater treatment train 100 canbe used as a retrofit to enhance existing systems. As illustrated inFIG. 1, the blackwater treatment train 100 can treat raw wastewater orwastewater first treated by an existing bioreactor.

As shown in FIGS. 1 and 2, a first influent 102 enters the blackwatertreatment train 100. Typically, this occurs directly from an installedblackwater collection system by way of a positive displacement pump.Alternatively, the first influent could enter from existing bioreactors.Initially, the first influent 102 enters a blackwater solids separationzone 108. While there are many ways to achieve a solids separation zone,it is preferred that the blackwater solids separation zone 108 furthercomprises a blackwater screening zone 110 and a clarifying zone 120.

The blackwater screening zone 110 performs initial solids separation. Itis preferred that the blackwater screening zone 110 utilizes a200-micron mesh rotary sieve 111 for initial solid separation. Screenedeffluent 112 can be held in an aerated equalization tank 114. Screenedsolids from the rotary sieve 111 are directed to either thermaldestruction device or to the sludge reduction zone 170 (discussedbelow).

The first influent 102 comprises traditional blackwater sources, butcould also include other sources. For example, in shipboard designs, itis preferred to include galley wastewater (sinks and grinders) as partof the first influent 102. In such cases, it is preferred that galleywastewater enter the blackwater treatment train 100 after first beingdirected through grease traps. Sources such as galley wastewater can beadded directly to the aerated equalization tank 114 as shown in FIG. 1.

Next, blackwater screening zone effluent 118 is pumped to a clarifyingzone 120. A preferred embodiment of the clarifying zone 120 is shown inFIG. 4. It is preferred that the clarifying zone 120 include amacerating pump 121, a flocculator 122, a clarifier, an air dissolvingpump 130 and a blackwater intermediate tank 135. The macerating pump 121helps homogenize the incoming feed to an optimum particle sizecompatible with the clarifier. An example of a macerator pump 121 isBarnes model number DGV2042L. An example of an air-dissolving pump 130is made by Nukini, model M25NPD-15Z. It is preferred that theair-dissolving pump 130 stream a small amount of air into the wastewateras the wastewater passes through the flocculator 122.

While many types of clarifiers are available, the preferred clarifier isa stainless steel hydraulic-lift dissolved air flotation device having acone-shaped top, which is referred to in this specification as ahydraulic separator 129. Effluent from the flocculator 122 flows intothe hydraulic separator 129 at the inlet 128. Air from theair-dissolving pump 130 is streamed through diffusers 134. When releasedfrom the pipe diffusers 134, dissolved air forms very fine bubbles thatmove upwards. This imparts an upward velocity to the fluid. As this aircontacts solid material it tends to agglomerate onto its surfaceimparting a positive buoyant force. This combination of upward fluidvelocity and positive buoyancy floats solids to the surface where theyare removed at specific intervals to the sludge reduction tank 172. Itis also preferred to add a solution of aluminum chlorohydrate by adosing pump to attain an optimum concentration (roughly 30 ppm), whichwill assist flocculation and floatation of solids.

Closing outlet valve 132 permits liquid wastewater that continues toflow through inlet 128 to raise the liquid wastewater level in thehydraulic separator 129. Ultimately, the liquid wastewater level willrise to the point that it force the separated sludge 126 (for thisspecification, the term “separated sludge” also includes water from thetop of the hydraulic separator 129) into the inverted cone region at thetop of the hydraulic separator 129. When the level is sufficiently high,separated sludge 126 (which has formed a floating blanket) is directedthrough the outfall pipe located at the top of the hydraulic separator129 into the sludge reduction tank 172. It is preferred to keep theseparated sludge in a liquid, flowable state so that it will flowwithout need for mechanical means. With a flowable separated sludge andhaving the top of the hydraulic separator 129 higher than the sludgereduction tank 172 inlet and normal operating level, sludge flows bygravity into the sludge reduction tank 172.

The sludge reduction tank 172 is segmented into two regions by a baffleplate 171. The baffle is oriented to form a barrier at the top of thetank and open at the bottom allowing communication between the two tankregions. One side of the baffle plate 171 forms a sludge reductionregion 173 and the other side of the baffle plate 171 forms an uptakeregion 175. Separated sludge 126 from the hydraulic separator 129 entersthe sludge reduction region 173 of the sludge reduction tank 172 nearthe top of the vessel. Separated sludge 126, so introduced, will retainits buoyancy and tend to rise to the top of the tank; while liquid isdisplaced downward. Clarified water, which can pass under the baffleplate 171 collects in the uptake region 175 before flowing by gravityinto the blackwater intermediate tank 135.

Ozonated finishing tank effluent 182 can be introduced into the sludgereduction tank 172, preferably in the sludge reduction region 173 insufficient quantity to oxidize the odoriferous material. A simple smelltest works here. The sludge reduction tank 172 treats sludge throughadvanced oxidation, with sludge characteristics transformed by ozonationand oxidation. This substantially reduces sludge volume by oxidation tocarbon dioxide gas, water and other materials. In addition, the sludgereduction tank 172 promotes solid and liquid separation. This step alsofurther clarifies the sludge mixture, forcing clarified water downwardin the device, around the baffle and into the clarified water uptakeregion 175. As additional sludge enters the sludge reduction tank 172from the hydraulic separator 129, an equal amount of sludge reductiontank 172 clarified water flows under the baffle and into the uptakeregion 175. When the water level reaches the uptake outfall 177, it isdirected to the blackwater intermediate tank 135.

The preferred sludge reduction tank 172 is cylindrical in shape. Forseparated sludge 126 flow rates of 0.5 gpm, the preferred sludgereduction tank would be approximately 8 feet tall and 3 feet indiameter, having a total ozonated volume of approximately 320 gallons,and providing a total retention time of 10 hours. In addition, thepreferred baffle plate 171 is a flat plate that is positioned within thecylindrical tank as a chord, running from inside wall to inside wall ofthe sludge reduction tank 172.

Reacted sludge 174 is directed to an onboard disposal system for thermaldestruction or held for overboard discharge at-sea or pumped ashore.Unlike most, if not all, sludge burning incinerators in use today, whichsuffer from odor problems from incineration of odiferous sludge frombioreactors, the sludge reduction zone 170 removes virtually all odorsfrom the reacted sludge 174, making it suitable for destruction bythermal devices.

When the outlet valve 132 is open, clarified water 124 flows into theblackwater intermediate tank 135. Likewise sludge reduction tank 172clarified water 176 from the sludge reduction zone 170 also flows intothe blackwater intermediate tank 135 and mixes with the clarified water124.

Clarification zone effluent 138 proceeds to a blackwater filtration zone160. It is preferred that the blackwater filtration zone 160 comprisesblackwater ultrafilters 162 and a blackwater flush tank 164. It ispreferred that the blackwater ultrafilters 162 be pressure fed externalplate and frame ultrafiltration membranes, such as the Pleiade Seriesmanufactured by Novasep Orelis. This membrane system has approximately753 square feet (70 square meters) of surface area/module, and canprocess up to 26.5 gallons-per-minute (6 m³/hr) per module. Systemcapacity may be increased by adding additional modules. The blackwaterultrafilters 162 should be periodically flushed with water produced bythe blackwater ultrafilters 162 and stored in the blackwater flush tank164.

Blackwater retentate 192, comprised of solids and other material thatdid not pass through the blackwater ultrafilters 162, is directed to thesludge reduction zone 170 for treatment, or bioreactor if installed.Blackwater permeate (i.e., effluent from the filters) 190 is directed toa blackwater advanced oxidation zone 140.

It is preferred that the blackwater advanced oxidation zone 140comprises an ozone generator 180, at least one, but preferably twoblackwater stirred reactors 142, 144, a blackwater disinfecting zone 150and a finishing tank 154. Prior to entering a stirred reactor, it ispreferred to infuse blackwater permeate 190 with ozone. Ozone can beproduced in a blackwater ozone generation zone 180 from ship service oilfree compressed air. Many different ozone generators could work. Forexample, the 240-g/hr ozone generator sold by Pacific Ozone, ModelR-SGA642, is preferred for treating 30 gpm flows of blackwater. Theozone can be dissolved into a pressurized stream of blackwater finishingtank effluent 156 for circulation to the blackwater stirred reactors142, 144 and the sludge reduction tank 172.

The preferred design of the blackwater stirred reactors 142, 144 isshown in FIG. 5. It is preferred to have blackwater stirred reactors142, 144 arranged in series. Within each blackwater stirred reactor 142,144, neutrally buoyant media 310 provide sufficient surface area for theinteraction and oxidation of dissolved ozone and soluble and insolubleorganic material. For treating 30 gpm flows, it is preferred to sizeeach blackwater stirred reactor 142, 144 to provide at least 11 minutesof residence time for the ozone oxidation reaction to occur.

Next, blackwater stirred reactor effluent 146 is directed to ablackwater disinfection zone 150 and treated with ultraviolet light.Ultraviolet radiation is advantageous because it damages the geneticstructure of bacteria, viruses, and parasites, making them incapable ofreproducing and/or killing them. In addition, ultraviolet radiationremoves ozone. It is preferred that the blackwater disinfection zone 150comprises a UV unit 152. It is preferred to use a medium pressure, highintensity UV unit 152 that produces polychromatic light for destructionof residual organic material, and disinfection. An example of such aunit is the Hyde Marine Model QMD100B1. The UV unit 152 can feature anautomatic cleaning wiper, which can be controlled by the control system450. The UV unit 152 also transforms any residual ozone into fastreacting species, such as hydrogen peroxide and hydroxyl radicalsfurther consuming any residual organic carbon based material. Inaddition, the destruction of residual ozone through this process allowsfor post-membrane filtration with ultra filtration where such filterswould not ordinarily tolerate ozone-enriched water without damage. UVtreated water is then directed to the finishing tank 154.

Ozone infused water in the finishing tank 154 is recirculated back tothe stirred reactors and UV unit until the level in the finishing tank154 reaches a predetermined level. Blackwater finishing tank effluent157 is then either pumped directly overboard if compliant, or pumped toonboard ship storage tanks for eventual discharge.

Blackwater finishing tank effluent 157 is typically colorless andodorless since ozone reaction with wastewater removes color and odors.This phenomenon is unique and important since most other technologiesused for treating wastewater such as bioreactors or membrane-bioreactorsdo not consistently produce effluent of this visual and olfactoryquality.

The use of gravity separation after grinding in this application isunique owing to the sludge reduction capabilities of the sludge holdingand sludge reduction tank 172. This allows the system to be operated inremote environments where sludge limitations and disposal are majorobstacles to system operation and standard treatment methods would beundesirable in part due to quantities of sludge produced

Alternate Embodiment of Blackwater Treatment Train

Alternatively, the blackwater filtration zone 160 could be moved fromits location prior to the blackwater advanced oxidation zone 140 andafter the clarification zone 120 to after the blackwater stirredreaction zone 140 as shown in FIG. 11. This alternate blackwatertreatment train is preferred when the total suspended solids (TSS) isless than 500 parts per million.

Preferred Graywater Treatment Train

The graywater treatment train 200 can be used as a standalone system totreat and reuse graywater or discharge all or part of the treatedgraywater. It is preferred to use the same component design for anygraywater treatment train component that has a counterpart in theblackwater treatment train and vice versa. The blackwater treatmenttrain 100 and graywater treatment train 200, however, are separatetreatment trains and wastewater is not comingled between the two trainsother than where expressly stated. In other words, the two treatmenttrains share only component design; they do not physically sharecomponents.

As shown in FIGS. 1 and 3, a second influent 202 enters the graywatertreatment train 200. Typically, the second influent 202 first enters agraywater solids separation zone 208. While there are many ways toachieve a solids separation zone, it is preferred to employ a screeningzone 210 after being pumped from a graywater holding tank (not shown).Preferably, the graywater screening zone 210 includes a resilientlymounted shaker screen 212 where separation of larger material occurs.The screen is mounted on an equalization tank 215. Screened solids 216collected from the graywater screening zone 210 are directed to thesludge reduction zone 170.

Next, the graywater screening zone effluent 218 is directed fromequalization tank 215 to a graywater filtration zone 220. It ispreferred that the graywater filtration zone 220 include pre-filters 222graywater ultrafilters 226, a backwash tank 224 and a graywaterintermediate tank 235.

The pre-filters 222 are preferably skid mounted, stainless steelvessels. The pre-filters 222 house polyethylene filter sleeves that willremove particulate material, reducing suspended solids and oil/grease inthe graywater stream. The redundant nature of the configuration ensuresan uninterrupted flow of filtered water to the graywater ultrafilters226. The system self-cleans using its own filtered water. In thepreferred embodiment, the pre-filters 222 are sized to removeparticulate larger than 5 micron in size, filters with this capabilityare available from Wastewater Resources, Inc, model number AQM 30.

Next, pre-filter effluent 223 is directed to the graywater ultrafilters222. The graywater ultrafilters 222 preferably use 20-nanometer ceramicmembranes such as those manufactured by the Novasep Orelis company ofLyon, France. When using ceramic membranes, surface wash water ispreferably ozonated and it is preferred not to use chlorine. Thepreferred source of ozonated surface wash water is from the graywaterfinishing tank 254. A pH neutralization chemical is preferred to adjustthe pH of the reclaim water to a pH of 7.5. For a 25-gpm design, it isexpected that between 50 and 80 gallons per month of pH neutralizer willbe required, volume is dependent upon pH of influent graywater.

Alternatively, the graywater filters 222 can use 20-nanometerpolysulfone synthetic membranes, such as those manufactured byWastewater Resources, Inc., model number PC1140. When using polysulfonesynthetic membranes (the alternative ultrafilter embodiment), it ispreferred to add chlorine to the backwash water for disinfection of themodules. If polysulfone synthetic membranes are used, it is preferred toadd a backwash tank 224 as shown in FIG. 3. Chlorine use for thebackwash tank 224 should not exceed 20 gallons per month for a 25-gpmsystem. A pH neutralization chemical is also preferred hereto adjust thepH of the reclaim water to a pH of 7.5. It is expected that between 50and 80 gallons per month of pH neutralizer will be required, volume isdependent upon pH of influent graywater.

For a 25-gpm design using polysulfone synthetic membranes (thealternative ultrafilter embodiment), a 94-gallon backwash tank 224constructed from ¼-inch polypropylene, such as the one manufactured byNavalis Environmental Systems, LLC, model number TK24-007-01, ispreferred. For a 25-gpm design using polysulfone synthetic membranes(the alternative ultrafilter embodiment), the membranes are each 12-inin diameter and 36-in in height with 1,140 ft² of surface area. Theprocess is designed to filter particles in the range of 0.02 to 0.04microns at up to 130 degrees F. with particulate loading not to exceed750 ppm. This will allow for backwashing at 24 to 30 minute intervalsfor two minutes. When using polysulfone synthetic membranes (thealternative ultrafilter embodiment), water for the backwash tank 224 ispreferred from the graywater finishing tank 254.

Graywater filter permeate 227 is collected in the graywater intermediatetank 235. Graywater intermediate tank effluent 238 proceeds to agraywater advanced oxidation zone 240. It is preferred that thegraywater advanced oxidation zone 240 comprise an ozone generator 280,at least one, but preferably two graywater stirred reactors 242, 244, agraywater disinfecting zone 250 and a graywater finishing tank 254.Prior to entering a graywater stirred reactor, it is preferred to infuseintermediate tank effluent 238 with ozone. Ozone can be produced in agraywater ozone generation zone 280 from ship service oil freecompressed air. Many different ozone generators could work. For example,the 120-g/hr ozone generator sold by Pacific Ozone, Model R-SGA442, ispreferred for treating 100 gpm flows of graywater. The ozone can bedissolved into a pressurized stream of graywater finishing tank effluent256 for circulation to the graywater stirred reactors 240, 242. A secondgraywater finishing tank effluent 258 can be directed to the graywaterbackwash tank 224 in the alternative ultrafilter embodiment that usespolysulfone ultrafilters.

The preferred design of the graywater stirred reactors 242, 244 is shownin FIG. 5. It is preferred to have graywater stirred reactors 242, 244arranged in series. Within each graywater stirred reactor 242, 244,neutrally buoyant media 310 provide sufficient surface area for theinteraction and oxidation of dissolved ozone and soluble and insolubleorganic material. It is preferred to size each graywater stirred reactor242, 244 to provide at least 5 minutes of residence time for the ozoneoxidation reaction to occur.

Stirred reactor effluent 246 proceeds to a graywater disinfection zone250 and disinfected with ultraviolet light. It is preferred that thegraywater disinfection zone 250 comprises a UV unit 252. It is alsopreferred to use a medium pressure, high intensity UV unit 252 thatproduces polychromatic light for destruction of residual organicmaterial, and disinfection. An example of such a unit is the Hyde MarineQMD100B1. The UV unit 252 can feature an automatic cleaning wiper (ascontrolled by the control system 450). The UV unit 252 also transformsany residual ozone into fast reacting species, such as hydrogen peroxideand hydroxyl radicals further consuming any residual carbon basedmaterial.

Graywater finishing tank effluent 290 may be reused 292 (e.g., directedback to laundry feed tanks for reuse as reclaimed technical water),blended 294 with graywater screening zone effluent 218, or discharged296 where regulations permit. The graywater finishing tank 254 alsoserves as source water of backwash for the backwash tank 224.

Graywater retentate 228 from the graywater filtration zone 220 can bedirected to the blackwater sludge reduction zone 170. Alternatively,graywater retentate 228 could be directed to a ships graywater transfersystem (not shown).

Preferred Stirred Reactor

FIG. 5 illustrates the preferred stirred reactor 300. It is preferred touse the stirred reactor 300 for the blackwater stirred reactors 142, 144and the graywater stirred reactors 242, 244. Referring to FIG. 5, thestirred reactor 300 comprises two cylindrically shaped chambers: acylindrical acceleration chamber 302 and a fluidized media chamber 304.The two chambers are mounted coaxially with respect to each other (i.e.,one inside the other). Two washer-shaped perforated plates 306 on eitherend cap the fluidized media chamber 304. One perforated plate is mountednear the top of the stirred reactor 300 and the other near the bottom.The volume between the perforated plates 306 houses fluidized media 310.These upper and lower perforated plates 306 hold the fluidized media 310in place and away from inlet and outlet ports. It is preferred that theperforations be sized to allow maximum flow while retaining thefluidized media 310 between perforated plates 306.

The cylindrical acceleration chamber 302 is smaller in cross section andmounted between the perforated plates 306. The preferred stirred reactor300 has inlet ports 308 and outlet ports 309 for admitting andexhausting the liquid. At the top of the stirred reactor 300, a mixer312 with a shaft 314 containing multiple blades 316 passes down thoughthe cylindrical acceleration chamber 302. The mixer 312 moves fluid inthe cylindrical acceleration chamber 302 down and out to the fluidizedmedia chamber 304 through the bottom perforated plate 306. Ozoneenriched fluids react with dissolved ozone and tiny, outgassed ozonebubbles which have formed on the fluidized bed, walls of the chamber,and float freely within the chamber. This enhanced oxidation reactorallows for advanced treatment in a small space.

The preferred stirred reactor 300 is for a 100-gpm graywater or 30-gpmblackwater treatment train is constructed from 316 stainless steel,approximately 3 feet diameter, 8 feet tall, having a fluidized mediachamber 304 volume of 282 gallons and a combined inside/outside chambervolume of 423 gallons. Thus, it is preferred that the fluidized mediachamber 304 be about ⅔ of the size of the combined inside/outsidechamber volume.

The preferred stirred reactor 300 is for a 25-gpm graywater and 10 gpmblackwater treatment train is constructed from 316 stainless steel,approximately 2 feet diameter, 5 feet tall, having a fluidized mediachamber 304 volume of 79 gallons and a combined inside/outside chambervolume of 118 gallons.

The stirred reactor 300 can be used alone, in series or in parallel.FIG. 1 illustrates two stirred reactors 300 connected in series. Whenconnected in series, the outlet port 309 of one stirred reactor 300 canbe connected to the series inlet port 308 if the second stirred reactor300.

The design of the advanced ozone reactor chambers and theirincorporation of fluidized media held in place by perforated platesallows the process to reach maximum oxidation efficiency in order tomeet modern standards. Earlier use of ozone in other designs limits theeffectiveness of the process and may fail to meet these more stringentstandards.

System Modularity

The treatment system 10 is expandable by design. It is preferred toconstruct a treatment system 10 from a standard family of 24-inch and36-inch diameter tanks. The 24 and 36 inch families are directed toretrofit design applications. In addition, FIG. 10 discloses anembodiment of a forward-fit blackwater component design. In aforward-fit design (i.e., new construction projects), larger diametertanks can be more easily assimilated into the ship or other structurethan in the typical retrofit situation. In this way, system treatmentcapacity is a function of the number of modular system componentsselected. Specific advantages of this design flexibility include:

-   -   1. System capacity is related to residence time in the reactor        vessels. The 100-gpm graywater treatment system shares common        stirred reactor, tank, pumps and system component (with        exception of ultrafiltration units) designs and materials with        the 30-gpm blackwater treatment system.    -   2. System components are mounted on either 28-inch or 40-inch        stainless steel squares that afford ease of mounting on ship        foundations.    -   3. System blocks can be arranged in a variety of configurations        to optimally use the space available, from a very compact square        to open linear based on available footprint.    -   4. Ease of rigging to the designated system compartment:        -   24-inch diameter system components fit through a 28″×28″            square or 40″ (1 meter) round opening        -   36-inch diameter system components fit through a 40″×40″            square or 57″ (1.5 meter) round opening    -   5. The arrangement enables design for easy access to areas        requiring routine maintenance.    -   6. The system is designed for growth. The modular nature of its        components enables ease of expansion. For example, the capacity        of the 25-gpm Graywater System could easily be increased by        addition of a filter module, and if necessary an additional        reactor.

An illustration of the building block nature of system capacity andinherent flexibility are provided in FIGS. 6-10.

Example: 25 gpm Graywater Embodiment

As previously noted, the water reclamation and treatment system 10 canoperate as a stand-alone system or as part or a more comprehensivetreatment train. The following sections describe examples of how thetreatment system 10 could be incorporated into different treatmenttrains. These examples should not be construed, however, as limiting theinvention to the example shown and described, because those skilled inthe art to which this invention pertains will be able to devise otherforms thereof within the scope of the disclosure set forth herein.

While a treatment system can be designed to meet existing conditions andneed, the following section summarizes an embodiment of the treatmentsystem sized to treat 25-gpm of graywater. A plan/footprint of thisembodiment is shown in FIG. 8. Referring now to FIG. 8, a first modulargroup 400 and a second modular group 410 of modules house the treatmentsystem. The first modular group 400 comprises two rows of five modules,where each module is 28-inches square and constructed from stainlesssteel. The second modular group 410 comprises one module 28-inches by41-inches. The modular sizing shown in this embodiment will permit atotal footprint of 54 square feet.

This modular design can be arranged in a variety of configurations tooptimally use the space available. The modular design enables ease ofexpansion. For example, the capacity of the 25-gpm system could easilybe increased by addition of a filter module, and if necessary anadditional stirred reactor. System components are mounted on 28-inchstainless steel squares that afford ease of mounting on shipsfoundations, and make a variety of configurations possible; from a verycompact square to open linear. For ship use, each component preferablyfits through a 28-inch opening for ease of rigging to the designatedsystem compartment. Further, the arrangement allows for easy access toareas requiring routine maintenance. Other modular embodiments are shownin FIGS. 6, 7, and 9.

It is preferred that the treatment system be fully automated and capableof remote control. It is preferred to use a control system 450, such asan Allen Bradley Programmable Logic Controller (PLC). The control system450 can interface with most ship interior communication and controlsystems providing system status where desired throughout the ship. Thecontrol system 450 can alert operational staff to issues requiringintervention. The control system 450 can also be configured forreach-back monitoring of system performance off ship through theaddition of networking components such as modems or ethernetconnections. This permits operators of the system to monitor and solveoperational issues as they arise.

In this example, treatment system components are preferably fabricatedfrom 316 Stainless Steel and should be impervious to ozone. System tanksare preferably constructed from ¼-inch 316 Stainless Steel. Internalpiping should be press fit 316 Stainless Steel or CPVC for the filterassembly only.

In this example, the graywater screening zone 210 uses a shaker screenmanufactured by Midwestern Industries, model Gyra-Vib MR 24 and a shakertank manufactured by Navalis Environmental Systems, LLC (“Navalis”),model number TK24-008-01; graywater ultrafilters 222 manufactured byWastewater Resources, Inc., model number PC1140; graywater intermediatetank 235 manufactured by Navalis, model number TK24-001-01; graywaterstirred reactors 242, 244 manufactured by Navalis, model numberTK24-003-01; UV unit 252 manufactured by Hyde Marine, model numberQMD100B1; a graywater finishing tank manufactured by Navalis, modelnumber TK24-002-01; graywater backwash tank 224 manufactured by Navalis,model number TK24-007-01; ozone generator 280 manufactured by PacificOzone, model number SGA 24 (60 g/hr); control system 450 manufactured byNavalis model number CP-GW-25; 30-gpm Process Pump manufactured byNikuni, model number M40NP; 50-gpm Transfer Pump manufactured by Gouldmodel number 11ASH262DO; 50-gpm Filter Charging Pump manufactured byGould, model number 4SH2E2CO; 100-gpm Filter Backwash Pump manufacturedby Gould, model number 8SH2H2CO; Ambient Ozone Monitor/Alarm/Shutdownmanufactured by IN USA, model number IN-2000-L2-LC.

It has been found that during normal operation of the treatment system,a system sized to handle 25-gpm of graywater operated in the order of 18hours a day can reclaim 100 m3/day of graywater for reuse.

Elevated ORP Reading and Relationship to Turbidity

The water reclamation and treatment system 10 will produce an effluentwith elevated ORP (oxygen reduction potential) and a lowered turbiditywhen in regulatory compliance as a by-product of its design. Therecirculation of final effluent through a stirred reactor 300 andsubsequently UV light in the disinfection zone allows the process to bemeasured through ORP and turbidity scales. Both of these effects can bemeasured and quantified by digital instruments currently available. Thepreferred instruments are George Fischer digital ORP meter andtransmitter, and the HACH 1720E digital Turbidimeter. These instrumentsyield a 4-20 ma output that can be monitored from the 450 (Program LogicController), which controls overall system operations.

The regulatory environment for discharge of treated wastewater into theocean varies from location to location around the world. Typically TotalSuspended Solids (TSS), Biochemical Oxygen Demand (BOD) and FecalColiform are the primary constituents regulated. TSS may be measureddirectly and immediately, during, and after treatment with existinginstrumentation. Both Fecal Coliform and BOD require sampling andlaboratory testing after waiting for a specified period of time. Thuswastewater treatment operators must wait the specified period of timebefore learning whether the treated wastewater has been sufficientlytreated to have permitted discharge. At least in part because ofdistrust in technology prior to this invention, some operators have beenknown to hold effluent until reaching water outside of regulatoryrestrictions—even when using in a certified, properly functioningtreatment device. As a result, real time effluent quality monitoring forthese two constituents is not currently achievable, creating uncertaintyas to the real-time continuous quality of effluent from wastewatertreatment.

For example, United States 33 Code of Federal Regulations Part 159subpart E establishes perhaps the most restrictive treated wastewatereffluent discharge standards in the world today. Applying to cruisevessels when in certain waters of the State of Alaska, these ships mustmeet effluent quality standards of not more than 30 milligrams per literTSS, 20 colony forming units per 100 milliliters Fecal Coliform and 30milligrams per liter BOD. Typically ships with marine sanitation devicescertified to meet these standards as a result of testing are permittedto discharge in these waters. However, spot-checking of ships by theState of Alaska has revealed that numerous ships are out of complianceeven though they are operating certified systems, and they are preventedfrom further discharge until corrective action is accomplished. Thecauses for failure are numerous, but lack of real-time effluentmonitoring capability has prevented instantaneous recognition ofout-of-compliant system operation so that action might be taken to ceasedischarging.

Given that a properly sized and properly functioning UV unit operatingin water of acceptable UV transmittance characteristics will effectivelydestroy or reduce to acceptable levels harmful bacteria, including theregulated Fecal Coliform, we have found that measuring ORP and turbidityof treated wastewater as soon as immediately after treatment can be usedto forecast BOD. Measurable indication of BOD treatment complianceeffectiveness at the time of discharge and displayed through the PLCcontrol center 450 is now possible because both ORP and turbidity can bemonitored immediately after treatment. Thus, to reduce the uncertaintyof treatment compliance time for wastewater, it is preferred to take thefollowing steps: (1) obtain a sample of effluent from a wastewatertreatment train, (2) measure Turbidity, and (3) Measure OxidationReduction Potential (ORP), and (4) comparing that to pre-determinedlevels based on site-specific regulations.

Continuous monitoring of ORP and Turbidity through installed measurementdevices connected to the PLC control center 450 indicates BOD levelswithin the effluent in real time. Indication of BOD (30 milligrams perliter) concentration compliance with 33CF159 subpart E requirement isprovided if ORP is greater than 200 mV and turbidity is less than 3 NTU.Compliance with the international standard specified in InternationalConvention for the Prevention of Ships Annex IV at 50 milligrams perliter is also indicated by ORP being greater than 200 mV and turbidityless than 3 NTU. This gives the operator an accurate active indicationof compliance with modern standards not available through another means.Other BOD regulatory criteria can be achieved in a similar manner on acase-by-case basis.

This unique relationship takes into account both the visible (suspendedsolids) and the invisible (dissolved organics) through the use ofturbidity, UV transmittance, and ORP. While the exact relationshipbetween measured UV Transmittance and BOD not yet known, it is expectedthat testing would shown it to be a critical parameter that will be ofmore use than turbidity to predict BOD compliance.

Visible organics will register in higher turbidity and dissolvedorganics will register in lower transmittance and reduced ORP levels.Biological treatment systems that do not use advanced oxidation lack thenecessary water chemistry to utilize this ratio and therefore cannot bemonitored for compliance in real time. The use of the oxidation reactionin the configuration listed yield ORP levels that are high enough toaffect a readable ratio. Previous attempts at this type of oxidation didnot yield a readable, repeatable ratio because the levels, if they wereobserved, were not high enough to affect a ratio. Since the readings areboth digital and inferred electronically, effluent quality data can thenbe easily transmitted from ship to shore for off ship effluent qualitymonitoring and system troubleshooting.

An alternate method for predicting BOD levels would be to recreate theunique advanced oxidation water chemistry by injecting ozone or otheroxidizer into the stream at the appropriate location, expose to UVlight, measure ORP and turbidity levels.

Although the invention has been described in detail with reference toone or more particular preferred embodiments, persons possessingordinary skill in the art to which this invention pertains willappreciate that various modifications and enhancements may be madewithout departing from the spirit and scope of the claims that follow.

1. A dual-train wastewater treatment system comprising: a blackwatertreatment train, the blackwater treatment train comprising a blackwateradvanced oxidation zone, and a graywater treatment train, the graywatertreatment train comprising a graywater advanced oxidation zone, whereineffluent from the graywater treatment train is reused and effluent fromthe blackwater treatment train is held, discharged, destroyed or furthertreated.
 2. The dual train wastewater treatment system of claim 1, theblackwater treatment train further comprising: a blackwater screeningzone in fluid communication with a blackwater clarifying zone, theblackwater clarifying zone in fluid communication with a blackwaterfiltration zone, and the blackwater filtration in fluid communicationwith a blackwater advanced oxidation zone.
 3. The dual train wastewatertreatment system of claim 1, the graywater treatment train furthercomprising: a graywater screening zone in fluid communication with agraywater filtration zone, the graywater filtration zone in fluidcommunication with a graywater advanced oxidation zone, wherein effluentfrom the graywater advanced oxidation zone is available for reuse astechnical water.
 4. The dual train wastewater treatment system of claim1, wherein the blackwater advanced oxidation zone comprises a blackwaterstirred reactor.
 5. The dual train wastewater treatment system of claim4, wherein the blackwater advanced oxidation zone further comprisesinfusing the clarification zone effluent with ozone prior to enteringthe blackwater stirred reactor, and oxidizing the clarified mixed liquorin the blackwater stirred reactor.
 6. The dual train wastewatertreatment system of claim 1, wherein the blackwater advanced oxidationzone comprises an ultraviolet unit.
 7. The dual train wastewatertreatment system of claim 1 further comprising a sludge reduction zone.8. The dual train wastewater treatment system of claim 7, the sludgereduction zone comprising: a sludge reduction tank, the sludge reductiontank having a baffle that separates the interior of the sludge reductiontank into a sludge reduction region and an uptake region, whereinozonated liquid enters the bottom of the sludge reduction region andsludge enters the top of the sludge reduction region, and wherein liquidin the uptake region can exit an outfall, the outfall located near thetop of the uptake region.
 9. The dual train wastewater treatment systemof claim 1 wherein the graywater treatment train does not comingle withthe blackwater treatment train.
 10. The dual train wastewater treatmentsystem of claim 1 wherein the first influent comprises graywater fromkitchen operations.
 11. The dual train wastewater treatment system ofclaim 3, further comprising the act (step) of directing a secondgraywater filtration zone effluent to the blackwater treatment train.12. The dual train wastewater treatment system of claim 3, the graywaterfiltration zone comprises the act (step) of ultrafiltration.
 13. Thedual train wastewater treatment system of claim 3, the graywateradvanced oxidation zone comprises a graywater stirred reactor.
 14. Thedual train wastewater treatment system of claim 13, the graywateradvanced oxidation zone comprising the acts (steps) of: infusing thegraywater filtration zone effluent (permeate) with ozone prior toentering the graywater stirred reactor, oxidizing the graywaterfiltration zone effluent (permeate) in the graywater stirred reactor.15. The dual train wastewater treatment system of claim 13, thegraywater advanced oxidation zone comprising the act (step) ofdisinfecting with ultraviolet light in a disinfection zone.
 16. The dualtrain wastewater treatment system of claim 13, further comprising theact (step) of directing a second graywater advanced oxidation zoneeffluent to the clarifying zone.
 17. The dual train wastewater treatmentsystem of claim 13, further comprising the act (step) of discharging athird graywater advanced oxidation zone effluent.
 18. A dual trainwastewater treatment system comprising: a blackwater treatment train,the blackwater treatment train comprising, a blackwater screening zonein fluid communication with a clarifying zone, the clarifying zone influid communication with a sludge reduction zone, the clarifying zone influid communication with a blackwater filtration zone, and theblackwater filtration zone in fluid communication with a blackwateradvanced oxidation zone, a graywater treatment train, the graywatertreatment train comprising, a graywater screening zone in fluidcommunication with a graywater filtration zone the graywater filtrationzone in fluid communication with a graywater advanced oxidation zone,and a conduit for sending filtered solids from the graywater filtrationzone to the sludge reduction zone.